Influence of the use of primer and light curing time on shear bond strength of orthodontic brackets

2011 ◽  
Vol 27 ◽  
pp. e12
Author(s):  
T. Munhoz ◽  
I.C. Correa
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Orthodontic Brackets ◽  
Curing Time ◽  
Light Curing

scholarly journals A Modified Photoactivation Protocol Using Two Simultaneous Light-Curing Units for Bonding Brackets to Enamel

2015 ◽  
Vol 26 (4) ◽  
pp. 393-397 ◽  
Author(s):  
Adauê Siegert de Oliveira ◽  
Rafael Correa Mirapalhete ◽  
Cássia Cardozo Amaral ◽  
Rafael Ratto de Moraes
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Curing Time ◽  
Thermal Cycles ◽  
Adhesive Remnant Index ◽  
Light Curing ◽  
Standard Deviations ◽  
Curing Method

<p>This study investigated the effect of a modified photoactivation protocol using two simultaneous light-curing units on the shear bond strength (SBS) of brackets to enamel. Metal brackets were bonded to bovine incisors using the resin-based orthodontic cement Transbond XT (3M Unitek). Four photoactivation protocols of the orthodontic cement were tested (n=15): Control: photoactivation for 10 s on each proximal face of the bracket at a time; Simultaneous: photoactivation for 10 s on both proximal faces of the bracket at the same time; One side-20s: photoactivation for 20 s at one proximal face of the bracket only; and One side-10s: photoactivation for 10 s only at one proximal face of the bracket. SBS was tested immediately or after 1000 thermal cycles. Adhesive remnant index (ARI) was classified. Data were subjected to two-way ANOVA and Student-Newman-Keuls' test (α=0.05). Pooled means ± standard deviations for SBS to enamel (MPa) were: 10.2±4.2 (Control), 9.7±4.5 (Simultaneous), 5.6±3.1 (One side-20s), and 4.6±1.9 (One side-10s). Pooled SBS data for immediate and thermal cycled groups were 6.3±2.6 and 8.8±5.2. A predominance of ARI scores 1-2 and 0-1 was observed for the immediate and thermally cycled groups, respectively. In conclusion, simultaneous photoactivation of the orthodontic cement using two light-curing units, one positioned at each proximal face of the bracket, yielded similar bonding ability compared to the conventional light-curing method. Photoactivation of the orthodontic cement at one proximal face of the bracket only is not recommended, irrespective of the light-curing time used.</p>

Effect of Shortened Light-Curing Modes on Bulk-Fill Resin Composites

2020 ◽  
Vol 45 (5) ◽  
pp. 496-505
Author(s):  
CS Sampaio ◽  
PG Pizarro ◽  
PJ Atria ◽  
R Hirata ◽  
M Giannini ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Light Output ◽  
High Mode ◽  
Resin Composites ◽  
Curing Time ◽  
Micro Computed Tomography ◽  
Polymerization Shrinkage ◽  
Light Curing

Clinical Relevance Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes. Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro–computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS. Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes. Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.

scholarly journals Prototype of a new tip developed to be coupled to dental light-curing units for optimizing bonding of orthodontic brackets and accessories

2013 ◽  
Vol 18 (6) ◽  
pp. 112-116
Author(s):  
Sergio Luiz Mota Júnior ◽  
Márcio José da Silva Campos ◽  
Marco Abdo Gravina ◽  
Marcelo Reis Fraga ◽  
Robert Willer Farinazzo Vitral
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Light Exposure ◽  
Orthodontic Brackets ◽  
Light Refraction ◽  
New Device ◽  
Halogen Light ◽  
Significant Difference ◽  
Light Curing

OBJECTIVE: development of a new device to be coupled to light-curing units for bonding orthodontic brackets and accessories, and test its efficacy in an in vitro mechanical trial. The inner surface of the device is mirrored and is based on physical concepts of light refraction and reflection. The main advantage of such device is the reduced clinical time needed for bonding and the low possibility of contamination during the process. METHODS: One hundred and twenty specimens were used for testing the shear bond strength of brackets bonded with the device. The Adhesive Remnant Index (ARI) was also determined. The sample was divided into 2 groups. In group 1 a halogen light-curing unit was used while in group 2 a led light-curing unit was used. Each group was then subdivided. In subgroups H1 and L1, a conventional light guide rod was used while in subgroups H2 and L2 bonding was performed with the mirrored device coupled to the tip of the guide light rod. RESULTS: The values obtained for the shear bond strength and the ARI in the subgroups were compared. Results showed that there was no statistically significant difference for the shear strength (p > 0.05) and the ARI (p > 0.05) between the subgroups. CONCLUSION: The tests of mechanical trials and the ARI analysis showed that the new device fulfilled the requirements for bonding orthodontic accessories, and that the time for bonding was reduced to half, being necessary only one light exposure.

scholarly journals Effect of Curing Time on the Bond Strength of Orthodontic Brackets Bonded by Light Cure Resin-Modified Glass Ionomer Cement: An In vitro Evaluation

2021 ◽  
Vol 14 (4) ◽  
pp. 1871-1876
Author(s):  
M.T. Maliael
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Orthodontic Brackets ◽  
Multiple Comparison ◽  
Glass Ionomer Cements ◽  
Curing Time ◽  
Glass Ionomer ◽  
Significant Difference ◽  
Resin Modified Glass Ionomer ◽  
Bond Strengths

This study was designed with the aim to evaluate the effect of curing time on the shear-bond strength of orthodontic brackets bonded using light cure Resin-Modified Glass Ionomer Cements (RMGIC). This class of cement when used for luting orthodontic brackets offers certain advantages when compared to the more commonly used resin cements. Intact natural teeth (premolars) extracted for therapeutic purposes as part of orthodontic treatment was sourced for use in this study. The teeth were equally divided into four groups four testing, Group 1 - brackets bonded with RMGIC and cured for 3 seconds, Group 2 - brackets bonded RMGIC and cured for 6 seconds, Group 3 - brackets bonded with RMGIC and cured for 9 seconds and Control group - brackets bonded with composite and cured for 15 seconds. A high intensity LED light source was used to cure the cements. The Shear-Bond strength of the brackets was evaluated using a universal testing machine. One-way ANOVA test and Tukey multiple comparison tests were done to compare the difference of Shear-Bond Strengths among the groups tested. The average Shear Bond Strength among study groups was 7.64±2.86 MPa. The ANOVA and Tukey multiple comparison tests could not identify a statistically significant difference in Shear-Bond Strengths among the groups. Curing time does not appear to have a statistically significant effect on the Shear Bond Strength of orthodontic brackets bonded using Resin-Modified Glass Ionomer Cements..

scholarly journals Effect of etching and light-curing time on the shear bond strength of a resin-modified glass ionomer cement

2010 ◽  
Vol 21 (6) ◽  
pp. 533-537 ◽  
Author(s):  
Ivan Toshio Maruo ◽  
Juliana Godoy-Bezerra ◽  
Armando Yukio Saga ◽  
Orlando Motohiro Tanaka ◽  
Hiroshi Maruo ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Polyacrylic Acid ◽  
Shear Bond Strength ◽  
Glass Ionomer Cement ◽  
Curing Time ◽  
Glass Ionomer ◽  
Resin Modified Glass Ionomer ◽  
Light Curing ◽  
Ionomer Cement

The aim of this study was to assess the influence of etching and light-curing time on the shear bond strength (SBS) and adhesive remnant index (ARI) of a resin-modified glass ionomer cement (RMGIC) upon debonding of orthodontic brackets. Sixty-eight bovine permanent incisors were obtained and embedded in acrylic resin. Edgewise metallic brackets were bonded to the teeth with Fuji Ortho LC RMGIC. The specimens were randomly assigned to 4 groups, using the following etching and light-curing times: G1: 10% polyacrylic acid and 40 s (control); G2: 37% phosphoric acid and 40 s; G3: 10% polyacrylic acid and 50 s; and G4: 37% phosphoric acid and 50 s. Shear test was performed at 0.5 mm/min and the ARI was assessed. G2 (3.6 ± 0.98 MPa) presented significantly higher (p<0.05) SBS than G1 (2.76 ± 0.86 MPa) and G4 (2.86 ± 0.68 MPa), and there was no statistically significant difference (p>0.05) between G2 and G3 (2.94 ± 0.67 MPa). ARI presented prevalence of scores 2 and 3 in all groups. RMGIC SBS enhanced with 37% phosphoric acid etching and 40 s light-curing time, but this did not occur when the light-curing time was increased, regardless of the acid used. RMGIC presented prevalence of failures at the adhesive/bracket interface.

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